1. Field of the Invention
This invention relates to a method and an apparatus for packaging mainly a trash sack in 20 sheets, 30 sheets or 50 sheets together or sheet-like matters such as synthetic resin film book cover, diaper cover, cloth wrapper and the like other than the trash sack. The invention relates particularly to a method and an apparatus for sealing a nose of a packaging flat tube band after opening the nose and inserting the matter into the tube.
2. Description of the Prior Art
A sheet-like matter of this kind is usually very thin, as using a film of 20 to 10.mu. or so in thickness. Such sheet-like matters are normally bundled in 20 sheets or 30 sheets, and are inserted in a packaging outer sack manually or mechanically.
However, such sheet-like matter is very thin and soft as mentioned above, therefore its periphery is easy to bend when inserted in the outer sack, and thus not only an external appearance is spoiled thereby but also the thickness of a package at a bent peripheral portion varies from other portions, and hence the difference in thickness is accumulated to lead to unstableness when a multitude of such packages are piled up to storage.
If the sheet-like matter is bent, then the portion must be corrected to straighten carefully by hand, which may involve a troublesome chore.
On the other hand, a mechanical way of insertion will require a tolerance on the outer sack satisfactory enough to cope with the thickness of holding plates which work vertically therefore. Moreover, the holding plates are capable of sticking a bottom of the outer sack to rupture it unless an inserting position of the holding plates is controlled accurately to the outer sack, thus requiring a high standard of skill for operating a control apparatus, and consequently normally a large outer sack with considerable tolerance is employed therefor.
However, the latter case entails an excessively large outer sack, therefore sheet-like matters piled up therein are easy to go out of order after packaging, and further a material of the outer sack is not utilized effectively.